(a) Field of the Invention
An exemplary embodiment of the present invention relates to a fuel cell system, and more particularly, to a compressed air cooling apparatus capable of cooling compressed air which is supplied to a fuel cell stack through an air compressor.
(b) Description of the Related Art
In general, a fuel cell system supplies hydrogen, which is used as fuel, and air, which is an oxidant, to a fuel cell stack, and electricity is produced by an electrochemical reaction of the hydrogen and the oxygen within the fuel cell stack. When a fuel cell system is mounted in a vehicle, and the vehicle is driven by operating an electric motor with electricity produced by the fuel cell stack.
Typically, a fuel cell system includes a fuel supplying system that supplies fuel to the fuel cell stack, an air supplying system that supplies air to the fuel cell stack, and a cooling system that removes heat produced from the fuel cell stack.
One type of air supplying system is an air compressor that compresses air and supplies the compressed air to the fuel cell stack, and a humidifier humidifies the compressed air with water produced from the fuel cell stack between the air compressor and the fuel cell stack.
However, under a high output power driving conditions of the fuel cell stack, the temperature of the air compressed by the air compressor increases to be about 120° C. due to a high compression ratio and a volume of air.
Since the aforementioned temperature is greater than 60 to 80° C., which is a normal driving temperature of the fuel cell stack, this creates problems in relation to humidification efficiency of the humidifier and driving efficiency of the fuel cell stack. Therefore, the fuel cell system needs to cool this high temperature compressed air which is supplied to the humidifier by the air compressor prior to supplying it to the stack.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.